The present invention relates to motor-driven devices for adjusting vehicle seats.
More particularly, the invention relates to a motor-driven adjustment device for a vehicle seat, the device comprising firstly a motor comprising a casing with two projecting endpieces which are rigid and opposite, being in alignment on a central axis, at least one of the endpieces having a rotary outlet member passing therethrough, and secondly a support to which the casing of the motor is fixed.
The motor casing is generally fixed to the support by means of a plurality of nuts-and-bolts, such that fixing the motor on the support requires installation time that is relatively lengthy, thus implying high installation and production costs.
In addition, since the motor is placed in a relatively small space, access to the screw-tightening zones is often difficult, thereby further increasing difficulty and lengthening installation time.
Furthermore, once the motor has indeed been fixed on its support, the connections via bolts frequently give rise to motor vibration being transmitted to the support and thus to the vehicle seat structure as a whole. It will thus be understood that when a user adjusts the position of the seat, this vibration can give rise to feelings that are uncomfortable and to noise that is objectionable.
A particular object of the present invention is to mitigate those drawbacks, by proposing a motor-driven adjustment device which can be assembled simply and quickly while reducing production costs.
The invention achieves this object by the facts that the two endpieces of the casing are received in non-rotatable manner in first and second viscoelastic sleeves which are resiliently engaged in respective first and second cradles formed on support plates constituting the support, and that said first and second cradles and the first and second sleeves are of shapes adapted to prevent the casing from moving on the support angularly, axially and radially relative to the central axis, said casing being connected to the support solely by means of the sleeves.
By means of these dispositions, the motor-driven adjustment device of the invention enables the elastically deformable sleeves of the casing to be engaged resiliently and snap-fastened directly in the cradles of appropriate shape of the support, with this requiring the operator to perform a single manual action that is simple.
Thus, the presence of the elastically deformable intermediate sleeves enables the casing of the motor to be assembled simply and quickly to the support, while significantly limiting the amount of vibration that is transmitted from the motor to the support, and thus to the vehicle seat.
In preferred embodiments of the invention, use may optionally be made of one or more of the following dispositions:
each sleeve is provided with a flange at one of its ends, said flange being disposed between one of the cradles of the support and the casing of the motor so as to prevent the motor from moving axially relative to the support;
each of said first and second cradles has a cylindrical internal bearing surface of diameter substantially identical to the outside diameter of the first and second sleeves and has an opening of a width that is less than the outside diameter of the first and second sleeves so as to enable the casing to be snap-fastened to the support and prevented from moving radially relative to thereto;
the first and second cradles are provided with respective notches for co-operating with respective keys formed on the outlines of the corresponding first and second sleeves so as to prevent the casing moving angularly relative to the support;
the outlet member of the motor comprises a rotary cable surrounded by a flexible sheath;
the flexible sheath is stuck to the inside of the corresponding sleeve;
the flexible sheath is stuck to the inside of the corresponding endpiece of the casing;
each rigid endpiece is provided with an external key received in a groove of complementary shape formed inside the corresponding sleeve in order to prevent said sleeve from moving angularly relative to the endpiece;
the two support plates are made as a single piece;
the second cradle is formed by a window having a closed outline substantially identical to the outline of the second sleeve, the second sleeve being elastically engaged in said window, and the first cradle has an internal bearing surface substantially identical to the outline of the first sleeve together with an opening of width that is smaller than the outline of said first sleeve so as to enable it to be snap-fastened to said first cradle and prevented from moving radially relative thereto;
each of the first and second cradles has an internal bearing surface that is substantially identical to the outline of the first and second sleeves, together with a respective opening of width greater than the smallest width of the outline of said first and second sleeves so as to enable them to be inserted in the first and second cradles, and the first and second sleeves are provided with respective keys for snap-fastening in corresponding notches formed in the internal bearing surfaces of the first and second cradles, by turning the casing of the motor about its central axis;
the support plate of the first cradle has a passage which, when the first sleeve is snap-fastened to the first cradle, is disposed in register with a first electrical connector provided on the casing of the motor, said passage being designed to receive a second electrical connector connected to the first electrical connector and designed to co-operate with said second electrical connector to lock the first sleeve in its snap-fastened position relative to the first cradle; and
the passage comprises two branches disposed on either side of the opening of the first cradle, said branches having respective free ends extending towards each other so as to enable the second electrical connector to be put into abutment between the first sleeve and said branch ends extending towards each other.
The invention also provides a motor vehicle seat having at least two portions that are adjustable relative to each other by means of a drive device connected to an outlet member of a motor-driven adjustment device as defined above.